Human hosts recruit more host-seeking deer flies (Diptera: Tabanidae) while walking than sitting

Biting flies can strongly influence the behaviour of their hosts, for example, there is evidence that some species may avoid harassment by reducing locomotory activity. We tested hypothesis potential hosts reduce attraction to deer remaining stationary—that movement reduces exposure new compared still. During early summer in central Ontario, Canada, we conducted 20-min trials where a human host either walked or sat quietly; tabanids were captured and counted each minute using hat outfitted with sticky trap. 10 treatment, total 868 flies, all genus Chrysops; capture while walking was nearly five-fold greater than sitting. trials, change catch rate also differed While sitting, mean declined rapidly (−16% per min) zero 20 min. In contrast, walking, this decline much more gradual (−5% min); after min, remained constant, at roughly half initial rate. These results are consistent hypothesis.